Electric heating apparatus for supplying heated fluid to a diver{3 s clothing

ABSTRACT

A method which is intended to supply heated fluid to divers&#39;&#39; clothing of the type including a fluid inlet connection communicating with internal fluid circulation passages in the clothing. The method includes the steps of pumping fluid from a source thereof into an enclosed chamber and directing the fluid in a flow path through the chamber to an outlet communicating with the inlet to the diver&#39;&#39;s clothing. Heat is supplied to the fluid in the flow path to raise the temperature of the fluid. The temperature of the fluid in the flow path subsequent to heating is sensed and the supply of heat to the fluid is reduced whenever the sensed temperature exceeds a predetermined value. A heating unit which is intended to supply heated fluid to divers&#39;&#39; clothing of the type provided with a fluid inlet connection communicating with internal fluid circulation passages in the clothing. The unit includes a housing having an enclosed main chamber. Pump means connected with the housing includes a pump inlet communicating with a source of the fluid and a pump outlet communicating with the main chamber for pumping the fluid therethrough. Chamber outlet means in the housing communicates with the main chamber and is adapted to be connected to the inlet connection of the diver&#39;&#39;s clothing. The pump outlet and the chamber outlet means are positioned at opposite ends of a fluid flow path through the main chamber. Heating means connected with the housing extends into the flow path for supplying heat to the fluid therein. Temperature responsive means connected with the housing extends into the flow path at a point downstream of the heating means. The temperature responsive means is operatively connected with the heating means to reduce the heat supplied thereby when the temperature of the fluid exceeds a predetermined value.

United States Patent H 13,55s,s52

[72] lnventors Leroy N. Larenzo Houston, Tex.; Mark P. Banjavich, NewOrleans, La.

[21 Appl. No. 738,458

[22] Filed June 20, 1968 [45] Patented Jan. 26, I971 [73] AssigneeTaylor Diving & Salvage Co., Inc.

New Orleans, La. a corporation of Louisiana,

[54] ELECTRIC HEATING APPARATUS FOR SUPPLYING HEATED FLUID TO A DIVERSCLOTHING 4 Claims, 5 Drawing Figs.

[52] U.S.Cl 219/211,

2/2.1, 126/204, 128/402. 165/46, 165/107, 219/306, 219/380 [51] Int. Cl..B63c 11/28, H05b 3/82 [50] Field of Search 219/302, 296-299, 528,303-309, 373, 380, 381, 382, 328, 331, 321, 330; 165/1, 104108, 120,64,46; 126/2042l0; 2/2.1; 128/379, 400-403, 254; 4/ 160, 165

[56] References Cited UNITED STATES PATENTS 3,349,223 10/1967 Barter219/505X 3,398,259 8/1968 Tregay et a1. 219/388X 3,417,226 12/1908Thomiszer 2 l9/505X Primary Examiner-A. Bartis At!0rneyBurns, Doane,Swecker & Mathis ABSTRACT: A method which is intended to supply heatedfluid to divers clothing of the type including a fluid inlet connectioncommunicating with internal fluid circulation passages in the clothing.The method includes the steps of pumping fluid from a source thereofinto an enclosed chamber and directing the fluid in a flow path throughthe chamber to an outlet communicating with the inlet to thediversclothing. Heat is supplied to the fluid in the flow path to raisethe temperature of the fluid. The temperature of the fluid in the flowpath subsequent to heating is sensed and the supply of heat to the fluidis reduced whenever the sensed temperature exceeds a predeterminedvalue.

A heating unit which is intended to supply heated fluid to diversclothing of the type provided with a fluid inlet connectioncommunicating with internal fluid circulation passages in the clothing.The unit includes a housing having an enclosed main chamber. Pump meansconnected with the housing includes a pump inlet communicating with asource of the fluid and a pump outlet communicating with the mainchamber for pumping the fluid therethrough. Chamber outlet means in thehousing communicates with the main chamber and is adapted to beconnected to the inlet connection of the divers clothing. The pumpoutlet and the chamber outlet means are positioned at opposite ends of afluid flow path through the main chamber. Heating means connected withthe housing extends into the flow path for supplying heat to the fluidtherein. Temperature responsive means connected with the housing extendsinto the flow path at a point downstream of the heating means. Thetemperature responsive means is operatively connected with the heatingmeans to reduce the heat supplied thereby when the temperature of thefluid exceeds a predetermined value.

10 animus m nus BACKGROUND OF TH E INVENTION This invention relates to amethod and apparatus for supplying heated fluid to a divers clothing.

ln performing underwater operations utilizing a diver clad in a divingsuit, problems are posed by the loss of the divers body heat to thesurrounding water. This problem is particularly acute when operating atappreciable depths where the water remains'at very low temperatures allyear round, but may also be encountered in shallow water during winteroperations. The rate of loss of body heat may severely restrict theamount of time for which the diver is able to work below the surface ofthe water before he becomes too cold to continue.

In order, therefore, to permit the diver to continue to work forprolonged periods immersed in cold water, diving suits have recentlybeen developed, having internal fluid circulation passages through whichheated fluid may be passed to warm adjacent portions of the divers body.It will be appreciated that diving suits of this type pose a uniquerequirement for supplying the heated fluid to the diving suit.

Although it would be possible to supply the heated fluid throughflexible fluid conduits extending to suitable apparatus positionedeither on a surface vessel or an immersed diving bell, such conduitswould be likely to severely restrict the mobility of the diver. Inaddition, the conduits would be vulnerable to snagging on obstructions,current action and to other hazards. It would, therefore, be desirableto provide a portable heating unit which could by carried by the diveron his person without significantly reducing his mobility.

One previous form of portable underwater unit for thermal purposes,provided portable back mounted gas cylinders for passing air through thewalls of a porous, padded diving suit to provide gaseous thermalinsulation about the divers body. Although apparatus of this type maysometimes prove satisfactory, certain operational disadvantages may beanticipated during prolonged periods of operation in the environmentpresently considered. For example, the fluid delivered by the cylindersis not in itself directly heated and thus could not supply heat to thediver to replace the loss of his body heat to the surrounding water.

Additionally, the period of operation of such a prior device would belimited by the gaseous capacity of the cylinders, as the gas afterpassing through the suit escapes into the surrounding water and is notrecirculated. With such an arrangement the period of operation of theunit may not be sufficiently long for sustained diving operations if thecylinder weight and dimensions are to be kept at a level consistent withunimpaired diver mobility.

Another problem associated with a gaseous, nonrecirculating system ofthe type described is that the escaping gas may tend to surround thediver with a stream of escaping bubbles which may seriously impair hisvisibility during working operations.

SUMMARY OF THE INVENTION It is, therefore, a general object of theinvention to provide a method and apparatus for supplying heated fluidto a divers clothing of the type described, which obviates or minimizesproblems of the type previously discussed.

It is another object of the invention to provide a heating unit forsupplying heated fluid to a divers clothing which is compact and may bereadily secured to the divers clothing and yet which provides asufficient heat output to enable the diver to continue to functionindefinitely even in very cold surround- It is a further object of theinvention to provide a heating unit for supplying heating fluid to adivers clothing which operates on a closed fluid cycle to minimize thepower required to be expended to maintain the diver in a comfortablecondition.

A heating unit according to one preferred embodiment of the invention,is intended for use with divcr's clothing of the type provided with afluid inlct connection communicating with internal fluid circulationpassages in the clothing. The heating unit includes a housing having anenclosed main chamber. Pumping means is connected with the housing. andincludes pump inlet means communicating with a source of the fluid, andpump outlet means communicating with the main chamber for pumping thefluid thereinto. Chamber outlet means in the housing communicating withthe main chamber is adapted for connection with the inlet connection ofthe divers clothing to supply fluid thereto. The chamber outlet meansand the pump outlet means are positioned at opposite ends of a fluidflow path through the main chamber. Heating means connected with thehousing extends into the flow path for supplying heat to the fluid inthe flow path to raise the temperature of the fluid. Temperatureresponsive means connected with the housing extends into the flow pathat a point therein downstream of the heating means. The temperatureresponsive means is operatively connected with the heating means forreducingthe heat supplied thereby whenever the tcmperature of the fluidexceeds a predetermined value. It will be appreciated that in thismanner heated fluid, up to but not exceeding a predetermined value, iscontinuously passed into the internal circulation passages in the diversclothing to keep the diver in a warmed condition.

In an important aspect of the invention the housing is of sufficientsize to be portable by the diver and is provided with securing means forsecuring the housing to the divers clothing.

Additionally, the pump means and the heating means are electricallyoperated and connected electrically to a source of electric powerpositioned remotely of the housing. The temperature responsive meansfurther includes an electrical thermostat for reducing the supply ofelectrical power to the heating means whenever the temperature of thefluid exceeds the predetermined value.

In more detail, the heating means includes independent first and secondheating means, with the thermostat means further including separatefirst and second thermostat means. The first thermostat means reducesthe supply of electrical power to the first heating means whenever thetemperature of the heated fluid exceeds a predetermined operatingtemperature, and the second thermostat means reduces the supply ofelectrical power to the second heating means whenever the temperature ofthe heated fluid exceeds a predetermined maximum temperature which ishigher than the predetermined operating temperature. With thisarrangement, one of the heating means operates substantially all thetime unless the predetermined maximum temperature is exceeded, while theother heating means turns on and off as necessary to maintain thepredetermined operating temperature, which is less than the maximumtemperature.

Significantly, the apparatus may be used with diving clothing of thetype previously described but wherein the diving clothing isadditionally provided with an outlet connection communicating with theinternal passages in the divers clothing for conducting the fluid away.For this purpose, the previously described housing unit further includesan enclosed second chamber not communicating with the main chamber. Thesecond chamber is adapted for fluid connection with the outletconnection of the divers clothing to receive fluid therefrom. The secondchamber is also in fluid communication with the pump inlet means so thatfluid is pumped from the second chamber to the main chamber. However, inan important feature of the invention, a selectively operable bypassvalve means is provided for passing a selectively controlled proportionof the fluid in the main chamber directly into the second chambcr. Thebypassed fluid passes from the second chamber to the pump inlet meansand thence back into the fluid flow path for further heating. In thismanner a selected proportion of the recirculated fluid is caused tobypass the diver's clothing and recycled directly. This selectivecontrol of the bypass valve provides an additional line control of thedivers temperature In another apparatus aspect, the invention isparticularly adapted for use in conjunction with a diving suit of thetype considered, further provided with pressurized breathing apparatus.The pressurized breathing apparatus is connected to a remote source ofgas under a pressure generally equal to the ambient water pressure atwhich the diver is positioned. The pumping, thermostat and heating meansare provided with electrical connections positioned outside thepreviously mentioned fluid filled chambers. The electrical connectionsare enclosed within gas-filled chambers which are connected with thedivers breathing apparatus connections. This provides a gas atmospheresurrounding the electrical connections. at a pressure substantiallyequal to the ambient water pressure surrounding the unit. This gaspressure diminishes the possibility of electrical arcing at theelectrical connections and, in addition, maintains the rigidity of theunit against collapse under the heavy external water pressuresencountered when operating at substantial depths.

A method aspect of the invention is intended to supply heated fluid to adivers clothing of the type including a fluid inlet connectioncommunicating with internal fluid circulation passages in the clothing.The method includes the steps of pumping the fluid from a source thereofinto an enclosed chamber and of directing fluid in a flow path throughthe chamber to an outlet communicating with the inlet to the diversclothing. Heat is supplied to the fluid in the flow path to raise thetemperature of the fluid. The temperature of the fluid in the flow pathsubsequent to heating is sensed and the supply of heat is reducedwhenever the sensed temperature of the fluid exceeds a predeterminedvalue.

When the divers clothing is of the previously mentioned type alsoincluding an outlet connection communicating with the internal fluidcirculation passages in the clothing, the method step of pumping fluidinto the main chamber is divided into a number of separate steps; Theseseparate steps include an initial step of receiving fluid from theoutlet connec' tion of the divers clothing in a second enclosed chambernot communicating directly with the main chamber. The fluid is thenpumped from the second chamber into the main chamber to enter the flowpath. A selectively variable proportion of the fluid in the main chamberis bypassed directly back into the second chamber to pass back to themain chamber for heating again. The provision of bypassing fluid in thismanner provides an additional method of controlling the temperature ofthe fluid in the divers clothing.

THE DRAWINGS A heating unit constructed in accordance with a preferredembodiment of the invention is illustrated in the accompanying drawingsin which:

FIG. 1 is a perspective view of a heating unit according to onepreferred embodiment of the invention shown mounted on a diver wearingclothing of the type with which the heating unit is intended for use;

FIG. 2 is a cross-sectional front view of the heating unit shown in FIG.1;

FIG. 3 is a cross-sectional top view of the heating unit shown in FIG. 2taken along the lines 3-3 therein;

FIG. 4 is a cross-sectional end view of the heating unit shown in FIG. 2taken along the lines 4-4 therein; and

FIG. 5 is a simplified schematic view of an electrical circuit formingpart of the heating unit shown in FIG. I.

DETAILED DESCRIPTION Referring to FIG. I, a heating unit forsupplying-heated fluid to a divers clothing is there shown. The heatingunit includes a housing. generally designated 2. portably mounted on thebody of a diver 4, by a belt 6 passing about the divers waist. The belt6 supports the housing 2 with its rear surface positioned generally overthe divers stomach. The diver 4 is wearing divers clothing of the typeprovided with internal fluid circulation passages (not shown) throughwhich fluid may be passed in heat exchanging relation with adjacentportions of the diver's body through the thickness of the passage walls.Heated fluid. in the present instance heated water, is supplied to theinternal fluid passages through a fluid inlet connection 8 provided onthe clothing. After the water has passed through the internalcirculation passages in the clothing it is delivered to a fluid outletconnection 10. The diver's clothing further includes a conventionalpressure helmet 12 provided with a breathing mix conduit 14. Thebreathing mix conduit 14 extends away to a remote source of breathingair provided at a pressure substantially equal to the ambient waterpressure at which the diver is operating. Additionally the diver isprovided with an electrical line 16 to the helmet containing the usualelectrical telephonic conduits as well as a supply line for electricalpower. I

The housing 2, shown inmore detail in FIG. 2, comprises a generallyrectangular, hollow, watertight container having left and right ends 15and I6. The housing 2 is covered by a thick layer of el'astomericmaterial I7 which provides thermal insulation for the heated liquid inthe housing. Additionally, the layer of material 17 enhances thewatertight qualities of the unit and provides protection against bumps,scuffing and the like.

The interior of the container is divided by partitioning into a liquidfilled main chamber A and a liquid filled, second chamber B. Thechambers A and B are not in direct fluid communication with each other.Liquid leaving the diver's clothing through the outlet connection 10passes through an inlet connector 20 secured to a generally horizontalupper surface of the housing 2, into the second liquid chamber B. Theliquid in the second chamber B is withdrawn through left and rightconduits 22 and 24, respectively, at opposite ends of the second chamberB by left and right, or first and second, electrically powered pumps 26and 28, respectively. The pumps 26 and 28 discharge into a commonchamber C which communicates with the main chamber A.

Two baffles 30 and 32 within the main chamber A cause the liquid passingtherethrough to follow a tortuously configured fluid flow path throughthe main chamber A towards a main chamber outlet 34. The main chamberoutlet 34 communicates, via an outlet connector 36 provided in thehousing 2, with the previously mentioned inlet connection 8 to thediver's clothing to deliver liquid from the main chamber A to the diversclothing.

To raise the temperature of the liquid in the chamber, left and right,or first and second, heating elements 38 and 40 are provided. Theheating elements which are positioned between and parallel to thebaffles 30 and 32 extending into the main chamber, supply heat to theliquid so that its temperature is raised. In this way a constant supplyof warmed liquid is delivered to the fluid circulation passages in thediver's clothing to keep the diver warm. I

To maintain control over the temperature of the liquid entering the suitfor the purposes of the divers comfort, the unit includes left andright, or first and second, electrical thermostats 42 and 44,respectively, which extend into the main chamber A above an upper sideof the baffle 32 remote from the heating units 38 and 40. Thethermostats 42 and 44 are responsive to the temperature of the heatedliquid in the fluid flow path subsequent to the application of heatthereto by the first and second heating elements 38 and 40.

As will be described in more detail hereinafter, the first thermostat 42is operatively connected with the first heating element 38 todiscontinue the supply of electrical power thereto whenever thetemperature of the liquid exceeds a predetermined operating value.Similarly, the second thermostat 44 is operatively connected with thesecond heating unit 40 to discontinue the supply of electrical powerthereto whenever the temperature of the heated fluid exceeds apredetermined maximum value which is higher than the predeterminedoperating temperature.

ln this manner, the second heating element continues to functioncontinuously unless dangerous overtemperaturc conditions occur, whilethe first heating element may cut off and on as frequently as isnecessary to maintain the heated liquid at the selected operatingtemperature.

Additional control over the temperature of the liquid passing throughthe divers clothing is provided by a selective ly operable bypass valve50. The valve 50 may be selectively opened to permit passage of aselected proportion of liquid directly from the main chamber A to thesecond chamber B as the liquid in the main chamber A (being incommunication with the outlet side of the pumps 26 and 28) is at higherpressure than the liquid in the second chamber B (communicating with theinlet side of the pumps). Thus a proportion of the liquid passingthrough the main chamber A is bypassed directly back into the mainchamber B thereby correspondingly reducing the rate of liquid flow outof the main chamber to the divers clothing.

As the outlet temperature of the liquid is controlled to a constantvalue by the thermostats a reduced rate of flow to the clothingcorrespondingly reduces the heat supplied to the diver. Thus, by openingand closing the bypass valve 50 manually, the diver is selectively ableto decrease and increase, respectively, the heat supplied to him in sucha manner as to optimize his comfort.

Significantly, this control, which is effected by a hand adjustment ofthe bypass valve 50 on the top of the unit, may be effected by the diverwhile he is immersed without requiring removal of the unit to thesurface for adjustment of the thermostats.

In another important aspect of the invention, the electrical connectionsto the first pump 26, the first heating element 38 and the firstthermostat 42 are all positioned outside the liquid filled chambers A, Band C, within an air filled left end chamber D forming part of thehousing 2. Similarly the electrical connection to the second pump 28,the second heating element 40 and the second thermostat 44 are allpositioned within an air filled right end chamber E positioned at theright end of the interior of the housing 2. The gas chambers D and E arein fluid communication with each other through a connecting gas conduit50. The chamber E is in fiuid communication with the previouslymentioned breathing mix connection 14 to the divers pressure helmet,with the result that the electrical connectors and the internal gaschambers are gas pressurized to a pressure generally corresponding tothe external ambient water pressure. lnthis way, collapse of the gasfilled portions of the housing under extreme external water pressures isprevented, and additionally the high prevailing internal gas pressureminimizes the possibility of arcing at any of the electricalconnections.

Detailed Structure The previously mentioned housing 2 (FIG. 2) comprisesa central subhousing 56 and left and right end subhousings 58 and 60,respectively. Each of the housings 56, 58 and 60 (FIG. 3) comprises anopen-ended tube having a generally fiat horizontal upper wall, spacedopposed front and rear vertical walls depending from the upper wall anda semicircular bottom wall.

To close the open ends of the central subhousing 56, left and rightvertically extending bulkheads 62 and 64, respectively, are provided.Each bulkhead extends across the adjacent open end of the centralsubhousing 56 and is fixedly secured thereto by welding or the like, toenclose the interior of the central subhousing 56 in lluidtightrelation.

To provide the previously mentioned second chamber B, an upper interiorwall 66 extends fixedly along and across the interior of the centralsubhousing 56 spaced below the upper wall thereof. The upper interiorwall 66, adjacent portions of the bulkheads 62 and the adjacent interiorwall portions of the central subhousing 56 together provide thefluidtight second chamber B.

The previously mentioned main chamber A is bounded at its lowerextremity by a lower interior wall 68 of the housing in fluidtightrelation therewith. The upper and lower interior walls 66 and 68,adjacent portions of the bulkhead 62 and 64 and the front and rear wallsof the central subhousing 56 together define the main chamber A.

To permit liquid to enter the main chamber A from the previouslymentioned common chamber C, a centrally positioned opening 70 isprovided in the lower interior wall 68. The housing 70 is defined by twospaced opposed edges 71 and 72 extending perpendicularly between. thefront and rear walls. I

The previously mentioned common chamber C extends downwardly from theopening 70 to the bottom wall of the central subhousing 56. The chamber6 is bounded by vertical, left and right walls 74 and 76, respectivelydepending from the lower interior wall 68 adjacent the edges 71 and 72of the opening 70.

The previously mentioned left, or first, pump 26 is positioned generallyhorizontally with its left end positioned outside thecentral subhousing56 and with the body of the pump extending sealingly through an aperturein the left bulkhead 62. The inner or right end of the first pump 26 isfixedly secured to the left inner bulkhead 74 with the outlet of thepump 26 communicating with the common chamber C.

Similarly the right, or second, pump 28 extends sealingly through anopening in the right bulkhead 64, and the left end of the pump 28 issecured to the right inner bulkhead 78 with the pump outletcommunicating with the common chamber C.

The pumps 26 and 28 are electrically powered, rotary. liquiddisplacement pumps giving a substantially constant rate of liquidthroughout at their operating voltage. ln the preferred embodiment thepumps are of the type manufactured by Bendix Corp. of Detroit, Mich.under the model designation No. 478148.

Liquid is supplied to the inlet ofv the pump 26 through the previouslymentioned conduit 22 which communicates with the left end of the secondchamber B with the conduit 22 being positioned outside the centralsubhousing 56. Similarly, liquid is supplied to the inlet of the rightpump 28 by the previously mentioned conduit 24 which communicates withthe second chamber B at the right end thereof, with the second conduit24 also being positioned outside the central subhousing 56.

As previously mentioned, heating for the liquid in its passage throughthe main chamber A is provided by the first and second heating elements38 and 40, each of which comprises a cantilever mounted, conventional,electrical immersion heater. The first heating element 38 extendssealingly through an aperture in the left bulkhead 62 into the interiorof the central subhousing 56 and extends horizontally thereacross inspaced parallel relation between the baffles 30 and 32 almost to theright bulkhead 64. Similarly, the second heating element 40 extendssealingly through the right bulkhead 64 into and across the interior ofthe central subhousing 56 almost to the left bulkhead 62. The heatingelements are disposed generally in the same horizontal plane with theleft heating element 38 spaced in front of the rear of the vertical wallof the central subhousing 56 and the right heating element 40 spacedbehind and parallel to the front vertical wall of the central subhousing56.

To ensure that the liquid gains the maximum amount of heat put out bythe heating elements, the previously mentioned baffles 30 and 32 definea fluid flow path which for a substantial distance, flows closely alongand adjacent the heating elements 38 and 40. For this purpose, the lowerbaffle 30 is spaced below and closely adjacent the heating elements. Thebafflc 30 has a closed left end wall 82 extending downwardly into fixedconnection with the lower interior wall 68 and extends between the frontand rear walls of the central portion 56 to cause fluid entering throughthe opening 70 to move toward the right end bulkhead 64. The lowerbafflc 30 ter' minates a short distance before the right end bulkhead 64so that the liquid is then deflected upwardly above the baffle 30 by thebulkhead 64.

The upper baffle 32 is spaced above the heating elements and extendsfrom the right bulkhead 64, to direct fluid along the heating elementstowards the left bulkhead 62. The upper baffle 32 terminates a shortdistance before the left bulkhead so that the liquid is then directedupwardly thereby above the baffle 32 to pass in a reverse direction,along the channel defined by the baffle 32 and the upper interior wall66.

The liquid passes over the previously mentioned left and rightthermostats 42 and 44, respectively, on its passage toward the outlet34. The left thermostat 42 passes sealingly through an opening in theleft bulkhead 62 while the right thermostat 44 passes sealingly throughthe right bulkhead 64. Both thermostats are generally horizontallypositioned and centralized vertically between the baffle 32 and upperinterior wall 66, with the left thermostat 34'bcing parallel to anddisplaced forwardly of the right thermostat 42. The left thermostat 42includes a horizontally projecting, adjusting screw 84 projecting intothe left gas chamber D. Similarly, the right thermostat 44 is providedwith a corresponding adjusting screw 86 projecting into the right endchamber E. Each of the thermostats is of a conventional type which maybe set to break an electrical circuit whenever the temperature sensed bythe thermostat exceeds a predetermined value set by adjustment of theappropriate one of the control screws 84 and 86.

The heated liquid leaving the main chamber .A passes through thepreviously mentioned main chamber outlet 34 which extends through thesecond channel B but is not in fluid communication therewith. From therethe fluid passes through the connector 36 to the inlet connection 8 tothe divers clothing.

The connector 36 may be of any suitable commercially available type andis provided with a conventional valve 90 which may be turned by hand toshut off flow through the connector 36.

Similarly the previously mentioned inlet valve 20, which is fixedlyconnected to the upper wall of the central subhousing 56 generallycentral thereof, is also provided with a conventional valve 92 which maybe turned by hand to shut off flow of fluid through the connector intothe second chamber 8.

As indicated earlier, the diver is provided with the bypass valve 50 forbypassing a proportion of fluid from the main chamber A directly backinto the second chamber B. The bypass valve 50 comprises a conicallyported valve seat 100 secured to the upper surface of the interior wall66, for placing the main and second chambers A and B in fluidcommunication. Flow through the valve seat 100 is controlled by aconical valving member 102 mounted in a valve body 104 secured to theupper wall of the central portion 56 of the housing. Opening and closingof the valving member 102 is controlled by the diver turning a handwheel106 to selectively vary the size of opening through the valve seat 100and hence the rate of passage of liquid therethrough.

It will be appreciated that as the valve 50 is opened to increase theproportion of fluid being bypassed, the remaining amount of fluid beingcycled through the diver's clothing is correspondingly reduced. However,as the temperature of fluid leaving the chamber A remains substantiallyconstant due to the action of the previously mentioned thermostats 42and 44, a reduced rate of flow of liquid through the suit must cause acorresponding reduction in the rate of supply of heat to the diver.Thus, if the diver feels too warm, he may reduce the heat being suppliedto him by simply opening the valve 50. Conversely, if he later starts tofeel too cold, he may increase the supply of heat to him byprogressively closing the bypass valve.

Very significantly, the bypassvalve 50 permits the diver to easily makeadjustments to the flow of fluid in such a way as to provide the mostcomfortable temperature in the diving clothing even while he is immersedduring diving operations when it would not be possible for the diver tocontrol his temperature by making adjustments to the thermostats.

Additionally, when the unit is about to be placed in use just prior todiving after a period of nonuse, the inlet and outlet valves may beentirely closed andthe entire output of the pump be recycled through thebypass valves and over the heating elements to very rapidly build up thetemperature of the body of liquid in the unit to operating temperature.The

unit may then be connected to the diver's clothing and the inlet andoutlet valves opened in the normal way. Thus, the unit may rapidly beheated in readiness for operation after a period of nonuse, byemployment of the bypass valve.

The outer ends of the various pumps and thermostats are enclosed withinthe end subhousings 58 and 60 which, as previously described, comprisetubular-bodies of the same peripheral configuration as the wall of thecentral subhousing 56 arranged in alignment therewith, Each of the endsubhousings 58 and 60 is closed at its outer, open end by a vertical endplate 110. The inner, open end of each of the end subhousings 58 and 60has secured thereto an outwardly directed. peripherally extending metalflange 112 fixedly secured in abutting, sealing contact to the adjacentoutwardly facing surface of the adjacent one of the bulkheads 62 and 64of the central subhousing 56. The interior of each of the end housings58 and 60 defines the two previously mentioned fluidtight gas filled,end chambers D and E, respectively.

To prevent collapse of the gas filled, end chambers D and E due to highexternal ambient water pressures, the end chambers are pressurizedinternally to a gas pressure generally equal to that of the externalwater pressure. For this purpose, the right, end subhousing 60 isprovided with an opening 112 which sealingly communicates with adetachable flexible conduit 114 (FIG. 1) to the divers breathing mixconnection 14 which, it will be remembered, communicates with a remotesource of breathing air at a pressure substantially equal to the ambientwater pressure. To permit the same pressure as is applied to the gasfilled right end chamber E to be applied to the gas filled left endchamber D, the previously mentioned hollow tubular pipes 50 (FIG. 4) aresealingly mounted in and extend between the walls 74 and 76. The gaspressure applied to the chambers D and E not only serves to maintaintheir rigidity against the external forces exerted by the waterpressure, but in addition, advantageously provides a high-pressureatmosphere which reduces any possible arcing of the electricalconnections to the pumps 26 and 28, the heating units 38, 40 and thethermostats 84 and 86.

In order to facilitate adjustment of the thermostat 44 when this unit isabove the surface and not in use, the previously mentioned breathing mixconnection opening 112 is aligned axially with the adjusting screw 86 ofthe second thermostat 44. When the breathing mix conduit 114 isdisconnected, a suitable tool (such as, for example, a screwdriver) maybe inserted through the aperture 112 to turn the screwv 86 to vary thetemperature setting of the thermostat 44.

To provide for similar adjustment of the adjustment screw 84 of thefirst thermostat 42, a second aperture 116 (FIG. 3) is provided in theleft end housing 58 aligned axially with the screw 84. The aperture 16is closed in watertight relation by a plug 118 when the unit isimmersed. On the surface, the plug 118 may be removed and a suitableadjusting instrument inserted through the aperture 116 to turn the screw84 to alter the predetermined temperature value for which the firstthermostat 42 is set.

Two electrical fuses 120 (FIG. 2) of a conventional type, are provided,positioned on opposite sides of the unit in the chambers D and E,respectively. Each of the fuses 120 is supported by bracket 122connected to the adjacent end subhousing, with the fuse in a generallyvertical orientation with its upper end adjacent the upper wall of thesubhousing. An aperture 124 in each of the end subhousings 58 and 60adjacent the upper end of each fuse 120 permits the fuse to be removedfor replacement, if necessary, when the unit is above surface. Whenimmersed, the openings 124 are closed by sealing plugs 126.

The electrical circuit controlling the operation of the variouselectrical elements thus far described. is shown in a simplifiedschematic form in FIG. 5. As will be seen, two similar but independentsubcireuits 127a and 12711 are provided. The subcircuit 127a includesthe first pump 26, the first heating element 38 and first thermostat 42,while the subcircuit [27h includes the second pump 28, the secondheating element 40 and the second thermostat 44.

Considering the first subcircuit 127a, electrical power is delivered tothe circuit from an electrical connector 128 (FIG. 2) connected via awatertight, plug-in electric cable 130 (FIG. 1) to the previouslymentioned electrical and telephonic supply line 16 to the divers helmet.The electrical connector 128 (FIG. includes an earth connection 132 tothe interior of the housing 2 and a live connection 134 to the one ofthe previously mentioned fuses 120 associated with the first subcircuit127a. One electrical output path from the fuse 120 delivers electricalpower to the first electrically-powered pump 26. Another outputconnection from the fuse 120 passes through the operating coil 136 of arelay 138 and through contacts (not shown) controlled by the firstthermostat 42 to earth.

When the temperature sensed by the first thermostat 42 is less than thepredetermined operating temperature for which the thermostat is set, thecontacts controlled by it-are closed so that a current path through therelay coil 136 exists. During this time, a pair of electrical contacts140 controlled by the relay coil 136 are closed to complete a currentpath through the first heating element 38 to earth, so that the heatingelement 38 provides heat to the liquid passing through the main chamber.When the temperature of the liquid exceeds the predetermined value, thethermostat contacts 42 open to deactivate the relay 130 which opens therelay contacts 140 to disconnect the source of electric power from thefirst heating element 38 which therefore ceases to deliver heat to theliquid. When the temperature drops below the predetermined operatingtemperature again, the thermostat contacts close to reactivate the relay130 to complete the power circuit to the heating element 38.

The second electrical subcircuit l27b contains corresponding circuitelements to the first subcircuit 127a and functions in a similar mannerto that described. However, the second thermostat 44 is set to cutoffthe power circuit to the second heating element 40 at a predeterminedmaximum temperature in excess of the previously mentioned operatingtemperature.

In this manner, the second heating element is turned off only when thetemperature of the liquid exceeds a dangerous maximum value rather thanbeing cutoff and on to maintain a predetermined operating value like thefirst subcircuit.

SUMMARY OF ADVANTAGES It will be appreciated that in following themethod and apparatus of the present invention to supply heated fluid todivers clothing, certain significant advantages are provided.

Of particular importance is the fact that the method and apparatusdescribed permits a diver's clothing to be supplied with heated fluidwithout requiring the provision of extra, bulky and extensive fluid andpower conduits extending to the diver from the surface or from a divingbell.

Also of major significance is the manner in which the invention providesfor virtually unlimited operation so long as the diver remains connectedto an electrical power source. thereby eliminating disadvantages ofprior systems which could function only for relatively restrictedperiods oftime.

Another particularly significant aspect of the invention resides in theprovision of the bypass valve which permits the diver, while he isimmersed, to vary the quantity of fluid flowing through the suit in sucha manner as to obtain the most comfortable temperature without anynecessity for the diver to return to the surface so that variouselectrical thermostats and the like may be adjusted.

The bypass valve is further advantageousin that it permits the unit tobe readily brought up to operating temperature after periods of nonusc,by simply recycling the fluid over and over the heating units prior touse until the fluid reaches the predetermined operating temperature.

Also important is the manner in which the invention utilizes a closedcycle liquid system to reduce the heating require ments. Additionallythe closed cycle system avoids producing clouds of bubbles or otherdisturbing phenomenon which might hinder a divcrs ability while workingor otherwise impair his freedom of action.

Also significant is the compact construction of the unit which enablesit to be attached to a divcrs clothing so that it may be moved abouteasily with the diver from one location to another, withoutsubstantially restricting the divers freedom ol'movement.

Although the invention has been described with reference to onepreferred embodiment, it will be appreciated by those skilled in the artthat numerous additions, deletions, substitutions, modifications andother changes not specifically disclosed or described may be made whichwill fall within the purview of the appended claims.

We claim:

1. Apparatus for supplying heat to a diver submerged in a body of water,the apparatus comprising:

a garment adapted to be worn by the diver and including:

internal fluid circulation passages through which fluid may be passed inheat exchanging relation with adjacent portions of the body ofthe diverthrough the thickness of the walls of said passages,

fluid inlet means communicating with said internal fluid circulationpassages, and

fluid outlet means communicating with said internal fluid circulationpassages;

a source of electrical power positioned remotely from said housing;

a source of gas under pressure generally equal to the am bient waterpressure at which the diver is positioned, said source of gas underpressure being positioned remotely from said housing,

a heating unit for supplying heated fluid to said internal fluidpassages in closed, fluid recirculating relationship, said heating unitcomprising:

a housing having,

an enclosed main chamber, and an enclosed second chamber; 7 main chamberoutlet means providing fluid communication between said main chamber andsaid fluid inlet means communicating with said internal fluidcirculation passages; second chamber inlet meansproviding fluidcommunication between said second chamber and said fluid outlet meanscommunicating with said internal fluid circulation passages;electrically powered pumping means mounted in said housing andcomprising: pump inlet means for withdrawing fluid from said secondchamber, and pump outlet means communicating with said main chamber fordelivering the fluid thereto, said chamber outlet means and said pumpoutlet means being positioned at opposite ends of a fluid flow paththrough said main chamber;

electrically powered healing means mounted in said housing and extendinginto said flow path for supplying heat to the fluid passing through saidmain chamber; temperature responsive electrical thermostat means mountedin said housing and extending into said flow path at a point thereindownstream of said heating means said thermostat means being operativelyconnected with said heating means to reduce the electrical supplythereto when the temperature of the fluid exceeds a predetermined valucisaid pumping means, said heating means and said thermostat means turtherincluding electrical connection terminals for connection of electricalpower to said pumping means, said heating means and said thermostatmeans, said electrical connection terminals being connected throughelectrical cable means to said source of electrical power positionedremotely from said housing and being positioned externally of said mainchamber; said housing further including,

gas chamber means extending about and enclosing said electricalconnection means and isolated from the fluids flowing through saidheating unit, and gas connection means in fluid communication with saidgas chamber and connected to said source of gas under pressure generallyequal to the ambient water pressure at which the dive is positioned;selectively and manually operable bypass valve means connected with saidhousing for passing a selectively variable proportion of the fluid insaid main chamber directly back into said second chamber; and valvemeans interposed between said main chamber outlet means and said fluidinlet means communicating with said fluid circulation passages. 2. Aheating unit as defined in claim 1 wherein said housing is of sufficientsize to be portable by the diver and securing means is provided adaptedto secure said housing to the divers clothingv 3. A heating unit asdefined in claim I further including.

buffle means connected with said housingextcnding into said main chamberfor configuring said How path to extend generally closely about saidheating means.

4. A heating unit as defined in claim I wherein.

said heating means further includes first and second independent heatingmeans; and said thermostat means Further includes independent first andsecond thermostat means operatively connnected with said first andsecond heating means respectively; said first thermostat means forreducing the supply of electrical power to said first heating meanswhenever the temperature of the heated fluid exceeds a predeterminedoperating temperature;

said second thermostat means for reducing the supply of electrical powerto said second heating means whenever the temperature of the heatedfiuid exceeds a predetermined maximum temperature higher than saidpredetermined operatingtcmperature. I

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 558,852 Dated January 26 1971 Inventor) Leroy N. Larenzo et a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover page, column 1, after "References Cited UNITED STATESPATENTS" cancel lines 1 2 and 3, and insert the following:

1,896,953 2/1933 HFJSSG].]...........-...... 165/ 16 ,9 5, 69 1/1933Carleton................ 219/2071. 59, 9 11 Tucker 0'0 211...... 219/2972,M18,283 1/119 17 1-111son.................. 21.9/35 1x ,5 1, 35 950Holmes.................. 219/297 ,710,9 /1955 Doniam.................2l9/298X ,753, 3) 7/ 956 Jepson. 219/212X 5,79 3/195 a k-s n. 219/365X2,982,8 0. 5/1961 maccmcmnuuuufl.... 219/2121 3, 27,908 1/1966 Pottcr'et al............2]9/325(UX) 331025709 9/1968 Shivers et 165/ 46XFOREIGN PA'JPENTS 102,0638 11/1933 Great Britain........... 128/ 861,632/1961 Great Britain........... 219/3 1,072,376 6/1967 GreatBr1.tain........... 219/5 Signed and sealed this 27th day of June 1972(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patent :nnu nnJnSn (HLSQ! .LH, .m.

1. Apparatus for supplying heat to a diver submerged in a body of water,the apparatus comprising: a garment adapted to be worn by the diver andincluding: internal fluid circulation passages through which fluid maybe passed in heat exchanging relation with adjacent portions of the bodyof the diver through the thickness of the walls of said passages, fluidinlet means communicating with said internal fluid circulation passages,and fluid outlet means communicating with said internal fluidcirculation passages; a source of electrical power positioned remotelyfrom said housing; a source of gas under pressure generally equal to theambient water pressure at which the diver is positioned, said source ofgas under pressure being positioned remotely from said housing; aheating unit for supplying heated fluid to said internal fluid passagesin closed, fluid recirculating relationship, said heating unitcomprising: a housing having, an enclosed main chamber, and an enclosedsecond chamber; main chamber outlet means providing fluid communicationbetween said main chamber and said fluid inlet means communicating withsaid internal fluid circulation passages; second chamber inlet meansproviding fluid communication between said second chamber and said fluidoutlet means communicating with said internal fluid circulationpassages; electrically powered pumping means mounted in said housing andcomprising: pump inlet means for withdrawing fluid from said secondchamber, and pump outlet means communicating with said main chamber fordelivering the fluid thereto, said chamber outlet means and said pumpoutlet means being positioned at opposite ends of a fluid flow paththrough said main chamber; electrically powered heating means mounted insaid housing and extending into said flow path for supplying heat to thefluid passing through said main chamber; temperature responsiveelectrical thermostat means mounted in said housing and extending intosaid flow path at a point therein downstream of said heating means, saidthermostat means being operatively connected with said heating means toreduce the electrical supply thereto when the temperature of the fluidexceeds a predetermined value; said pumping means, said heating meansand said thermostat means further including electrical connectionterminals for connection of electrical power to said pumping means, saidheating means and said thermostat means, said electrical connectionterminals being connected through electrical cable means to said sourceof electrical power positioned remotely from said housing and beingpositioned externally of said main chamber; said housing furtherincluding, gas chamber means extending about and enclosing saidelectrical connection means and isolated from the fluids flowing throughsaid heating unit, and gaS connection means in fluid communication withsaid gas chamber and connected to said source of gas under pressuregenerally equal to the ambient water pressure at which the dive ispositioned; selectively and manually operable bypass valve meansconnected with said housing for passing a selectively variableproportion of the fluid in said main chamber directly back into saidsecond chamber; and valve means interposed between said main chamberoutlet means and said fluid inlet means communicating with said fluidcirculation passages.
 2. A heating unit as defined in claim 1 wherein,said housing is of sufficient size to be portable by the diver, andsecuring means is provided adapted to secure said housing to thediver''s clothing.
 3. A heating unit as defined in claim 1 furtherincluding, baffle means connected with said housing extending into saidmain chamber for configuring said flow path to extend generally closelyabout said heating means.
 4. A heating unit as defined in claim 1wherein, said heating means further includes first and secondindependent heating means; and said thermostat means further includes,independent first and second thermostat means operatively connnectedwith said first and second heating means respectively, said firstthermostat means for reducing the supply of electrical power to saidfirst heating means whenever the temperature of the heated fluid exceedsa predetermined operating temperature; said second thermostat means forreducing the supply of electrical power to said second heating meanswhenever the temperature of the heated fluid exceeds a predeterminedmaximum temperature higher than said predetermined operatingtemperature.